Health clubs have become popular as people have sought a pleasant environment in which to exercise and socialize. Most health clubs offer various machines for aerobic exercise, including stationary bicycles, rowing machines and treadmills, as well as weight lifting machines. While such machines may provide a vigorous workout when properly used, they offer limited incentive and encouragement to the user to exert a maximum effort. The aerobic exercise machines are used individually and the user can only compete against himself. Also, the machines do not record the past performance of the user. Many users become bored with such repetitive exercise, and may eventually stop using the equipment, especially without the incentive of data which would show increases in the user's level of fitness over time.